In United States v. Patane, 542 U.S. 630 (2004), in a divided opinion, the United States Supreme Court held that the failure to give Miranda warnings did not require suppression of evidence that was the fruit of a suspect's unwarned but voluntary statements. A three-justice coalition expressly so held. Patane, 542 U.S. at 633-34. Two other justices agreed with that ruling, but found it unnecessary to determine, as the lead opinion had, whether the failure to warn should be considered a violation of Miranda itself. Id. at 644-45 (Kennedy and O'Connor, JJ., concurring in the judgment). The Court made it clear that Miranda is a prophylactic rule designed to effectuate the right a suspect has not to be compelled to testify against himself at a criminal trial. Patane, 542 U.S. at 636-37. These concerns are not implicated by admitting into evidence the fruits of unwarned statements. See id. at 638-39. In fact, statements taken in violation of the Miranda rule have long been held to be admissible in evidence for impeachment purposes. Patane, 542 U.S. at 639. Thus, using unwarned statements to obtain physical evidence is no more a violation of the constitution than using unwarned statements for other proper purposes, i.e., purposes not involving use as evidence in the prosecution's case in chief. Id. at 640, 641 and 645 (Kennedy and O'Connor, J.J., concurring in the judgment). The Court limited its ruling to voluntary statements, as the fruits of involuntary statements are frequently excluded for other reasons. See id. at 634, 639, 644.